Cross plot of δ18O carbonate vs δ13C carbonate of Baltica and Laurentia records. Although Baltica has lower Δ47-Temperatures than Laurentia, both have similar ranges in δ18O carbonate.Credit: Proceedings of the National Academy of Sciences (2024)
Posted on 09/05/2024 3:21:02 PM PDT by SunkenCiv
An international team of ocean, Earth and marine scientists has found evidence supporting a theory that a certain oxygen isotope ratio in seawater has changed slowly over the past 540 million years. In their study, published in the Proceedings of the National Academy of Sciences, the group analyzed rocks from the Ordovician period.
Over the past half-century, earth scientists have debated the possibility of changes in the ratio of 16O to 18O (written as δ18O) in seawater over the past 540 million years. Some have put forth arguments claiming no change has occurred, while others report evidence that it has increased.
The researchers in this study found new evidence supporting the latter theory. They note that settling the argument is important because the ratio impacts the prediction of ocean temperatures during certain times in the distant past.
Researchers believe that there are two factors that can force changes to the ratio—hydrothermal alteration due to hot water coming into contact with certain rock formations, and to a lesser extent, weathering of continental crust.
To learn more, the research team pulled drill cores from a location on Estonia's Baltic basin. Those, along with rock samples collected at above-ground sites in the region, were analyzed using clumped isotope thermometry—a technique that can measure the 13C that has become bound to 18O encased in carbonate minerals. It can be used to estimate ocean temperatures because the binding process is temperature dependent.
The measurements showed that during the Ordovician, the seawater in which the rocks had been covered had a lower δ18O and was cooler than previous estimates had suggested, which shows that the ratio has been slowly changing over the past half-billion years.
(Excerpt) Read more at phys.org ...
Cross plot of δ18O carbonate vs δ13C carbonate of Baltica and Laurentia records. Although Baltica has lower Δ47-Temperatures than Laurentia, both have similar ranges in δ18O carbonate.Credit: Proceedings of the National Academy of Sciences (2024)
Sweet - Love Is Like Oxygen
https://www.youtube.com/watch?v=zRgWvvkSvfk
“theory”
What are the units in the graph?
“Then all collapsed, and the great shroud of the sea rolled on as it rolled five thousand years ago.”
― Herman Melville, Moby-Dick or, The Whale
And all this time I thought it was 539 million years. Who know?
And it turns out that it’s going to reach Earth-killing levels in 2031 ... unless we give up all electricity generation worldwide.
Join the Zero Electron Movement and raise taxes to 99.9%.
In go plants, life and sunlight. Out comes oxygen.
Totally AWESOME, DUDE!
That article brings back memories of geochemistry classes 40 years ago.
Very interesting. Have you noticed a political bias in their conclusions? If so, what are you conclusions?
No units. They’re ratios, so the units of measurement cancel out when the ratios are calculated.
“New evidence supports theory that oxygen isotope ratio in seawater slowly increased over last 540 million years”
I had nothing to do with that. Honest.
Of course they’re ratios. Log of the ratio. Zero on x axis is one. No increase or decrease.
But ratios of what to what?
Look up “oxygen isotope ratios” in Wikipedia. It will explain better than I can.
Thanks.
Actually I just noticed the delta.
I’m partly to blame for the methane rise.
So, are we all going to die, or what?
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